The cw laser activated flow method is applied to the planarization of phosphosilicate glass passivatedn‐channel metal‐oxide‐semiconductor field‐effect transistors with various device geometries. Flow is demonstrated over a range of raster scan velocities and at all principal CO2laser wavelengths. Device characteristics, namely, threshold voltage, junction breakdown voltage, and transconductance, are essentially unaffected by the laser irradiation, whereas the polycrystalline silicon interconnect resistance is reduced by about 20%. The effect of thermal conductivity of the phosphosilicate glass on the laser flow threshold is shown.